Career Summary

Biography

Associate Professor Patricia Saco’s research over the past years has focused on understanding the impacts of human pressures and climate variability and change on hydrology, land and soil resources. Her early research at the University of Illinois, supported by an earth-science postgraduate fellowship from NASA, focused on understanding the impact of river network configuration on the hydrologic response of catchments at various spatial scales. This work had a remarkable international impact which was recognized with two prestigious international prizes the UCOWR (University Council in Water Resources) best dissertation award and the Lorenz Straub (University of Minnesota) award. Numerous applications and extensions of this work have been since pursued in collaboration with research groups and government agencies.

An example worth highlighting is the study of the Illinois River basin carried out by the Illinois State Water Survey (ISWS). In this work,Patricia collaborated with colleagues from the ISWS to develop a comprehensive watershed-scale model to simulate the hydrology and water quality of stream reaches within the Illinois River Ecosystem Restoration Project. The study, funded by the U.S. Army Corps of Engineers, Rock Island District and the Illinois Department of Natural Resources, was used to assess flow characteristics throughout the catchment, potential effects of changes in land use and climate, changes due to project alternatives, and restoration alternatives.

Patricia’s more recent research on Ecohydrology and Ecogeomorphology at the University of Newcastle has focussed on the analysis of the interactions and feedbacks between water resources, vegetation, soils, and landforms. Her approach to research includes a combination of theoretical analysis, modelling and field work. The ultimate goal of her work is to improve the understanding of the relations between hydrologic processes and the underlying observed soil, ecologic and landform structures, and to develop ecohydrologic predictive capabilities that can be used in practical management and engineering solutions to the many environmental problems that we are currently facing. Recent applications of this work has been pursued in collaboration with colleagues from the NSW office of Environment and Heritage (Rivers and Wetlands Unit) and Newcastle Coal Infrastructure Group.

Patricia’s research is broad, highly interdisciplinary and with local and international impact. She has tackled problems of hydrology of US catchments, landscape and vegetation coevolution in arid and semi-arid Australia and US, large-scale hydroclimatology processes affecting Australia and the South Pacific, sediment connectivity transport and erosion in rivers and catchments in US, Australia and South America, climate change impacts on Australian coastal and inland wetlands and optimization of water allocation for habitat hotspots in managed rural systems.

Her recent work in ecogeomorphology exploring interactions between landforms and vegetation patterns has led to the development of a novel modelling framework, suitable for the identification of degradations risks in both humid and arid landscapes. This research prompted invitations to deliver several seminars in Australia, US and Europe and, more importantly, the establishment of key international research collaborations worldwide. Further evidence of recognition for this work is given by the award in 2014 of an Australian Reseach Council Future Fellowship at FT2 level.

Some of Patricia’s current collaborative research is also having great influence in the area of Climate Change effects on coastal ecosystems, not only in Australia but also in other regions of the Pacific where Climate Change effects are critical like the Pacific Islands and Peru. Her research in this area has been highlighted in some of the most prestigious research meetings (European Geoscience Union, American Geophysical Union) academic publications (Nature Communications) media (Australian Geographic, ABCnews) and more recently in the Australian Research Council report “Making a Difference: Outcomes of ARC supported research 2017-18”.

Motivated by the need to understand large-scale hydrologic response, significant research has been directed toward the identification of coherent regions using characteristics of ... [more]

Motivated by the need to understand large-scale hydrologic response, significant research has been directed toward the identification of coherent regions using characteristics of streamflow variability. Typically, these regions are delineated using principal component analysis on streamflow. This method does not account for differences in temporal scales of fluctuations embedded in the time series. To capture this, we use wavelet spectral analysis. Wavelet spectra from the specific stream flow series are obtained for outflow binned at 3°-length segments along the border of the conterminous United States. Rotated principal component analysis is performed on the wavelet spectra to obtain clusters of segments that exhibit similar distribution of variability across scales. Three physically distinct modes explain over 89% of the variability. Two of the modes identified are associated with high variability at seasonal scales, and the third is associated with high variability at small timescales. The runoff generation mechanisms underlying the observed modes of multiscale variability of various regions are also discussed. Each of these coherent modes of multiscale variability indicate the existence of regions with similar scales of fluctuations that are located geographically apart, as well as regions located geographically close with dissimilar scales of fluctuations.

Pool-riffle sequences are one of the most common geomorphological features in many streams and provide important habitat diversity both in terms of flow and substrate. The conditi... [more]

Pool-riffle sequences are one of the most common geomorphological features in many streams and provide important habitat diversity both in terms of flow and substrate. The conditions for their formation and self-maintenance are still the subject of active research, but it has become clear in later years that a combination of three mechanisms: 1) stage-dependent flow conditions, 2) three-dimensional flow patterns and 3) selective sediment transport over a mobile bed, can explain the resilience and ubiquity of pool-riffle sequences observed in the field. In this paper, we analyze the importance of these three mechanisms using different combinations of stage-dependent three-dimensional flow patterns in pool-riffle sequences and sediment size distributions obtained in both pools and riffles. Self-maintenance mechanisms are identified by evaluating erosional or depositional tendencies in pools and riffles for different flow conditions using local values of bed shear stress and their corresponding fractional sediment transport volumes. Self-maintenance is directly linked to episodes of pool erosion and riffle deposition and we use the term sediment transport reversal rates to indicate this situation, rather than velocity reversal or shear stress reversal that only consider flow variables. This approach allows us to compare, for the first time, the relative importance of each of the mechanisms and their role in the self-maintenance of these bedforms, which can vary from site to site. Computations are performed using existing field, laboratory and numerical simulation data from several study sites. We discuss the limitations of our approach and the extensions to more complex field cases.

This work presents preliminary results of implementing a quasi-2D hydrodynamic module (VMMHH 1.0) to simulate flows and flooding patterns throughout the Macquarie Marshes, south e... [more]

This work presents preliminary results of implementing a quasi-2D hydrodynamic module (VMMHH 1.0) to simulate flows and flooding patterns throughout the Macquarie Marshes, south east Australia, in order to assess habitat requirements. The model uses an interconnected cell scheme that solves mass conservation and uses simplified versions of the momentum equations to represent flow between cells. This model has been used before to assess geomorphological changes in large river floodplains and vegetation evolution in estuarine wetlands, showing results consistent with cases of gradual floodplain inundation following overbank flow. The simplified characteristics of the quasi-2D model allow for an adequate representation of hydrodynamic processes with similar performance of other higher dimensional models. Model results and computational times are compared with outputs from a conventional 1D/2D model (MIKE FLOOD) applied to the same domain showing that the VMMHH 1.0 is adequate for representation of floods in the Macquarie Marshes.

Moreno De Las Heras M, Saco PM, Willgoose GR, 'Linking surface hydrological connectivity patterns with landscape functionality in semiarid Australian ecosystems', Proceedings of the 34th World Congress of the International Association for Hydro- Environment Research and Engineering: 33rd Hydrology and Water Resources Symposium and 10th Conference on Hydraulics, Brisbane, QLD (2011) [E1]

Chen M, Willgoose GR, Saco PM, 'Estimating temporal soil moisture dynamics using the HYDRUS-1D and IBIS models', Proceedings of the 34th World Congress of the International Association for Hydro- Environment Research and Engineering: 33rd Hydrology and Water Resources Symposium and 10th Conference on Hydraulics, Brisbane, QLD (2011) [E1]

Research Collaborations

The map is a representation of a researchers co-authorship with collaborators across the globe. The map displays the number of publications against a country, where there is at least one co-author based in that country. Data is sourced from the University of Newcastle research publication management system (NURO) and may not fully represent the authors complete body of work.